Bruney, handed a two-run lead in the top of the eighth, couldn't hold on as he was booed off the mound after allowing the tying runs to score.
The Yankees, however, scored three times in the bottom of the inning and nailed down their sixth straight win with an 8-5 victory over the Mariners at the Stadium.
Rivera, who notched his 500th save Sunday night, pitched the ninth to record No. 501 and his 19th of the season.
Alex Rodriguez broke a 3-3 tie with one out in the seventh, driving a 2-and-2 pitch from righthander Chris Jakubauskas deep into the leftfield seats to give the Yankees a 5-3 lead. It was Rodriguez's 565th home run, leaving him four short of Rafael Palmeiro for 10th on the all-time list.
Johnny Damon had led off the inning with a double down the leftfield line.
Despite Phil Hughes mowing down the Mariners in order in the seventh, Girardi inserted Bruney in the eighth. Bruney immediately got into trouble, allowing three straight singles and he walked off the mound with the score tied at 5.
But Hideki Matsui started the bottom of the eighth against Sean White with a double to right-center, the first of four straight hits in the three-run inning. Melky Cabrera drove in one run with a double and Derek Jeter brought home two runs with a single to left.
Joba Chamberlain got the start and pitched decently.
"For him, the key is, stay out of long counts and don't walk people," Girardi said of Chamberlain before the game.
Chamberlain did only one of the two. He walked three - not bad - in 51/3 innings, but consistently was in long counts. He threw 96 pitches - 55 strikes - in allowing nine hits and three runs.
The Yankees scored two unearned runs off Brandon Morrow in the second. Robinson Cano and Jorge Posada started the inning with consecutive singles. Matsui was next and when Chris Woodward bobbled his grounder, then threw wide of first, Cano scored and Posada advanced to third. Posada came home on Cabrera's deep fly to center to make it 2-0.
The Mariners cut it to 2-1 in the third when Ronny Cedeno led off the inning with a home run to left, the ninth homer Chamberlain has given up this season.
The Yankees added to their lead in the third, though only by one run after having the bases loaded with none out. The run scored on a groundout by Cabrera.
Ichiro Suzuki led off the Marinerrs' fifth with an infield single and promptly stole second and third. He came in on Russell Branyan's line single to right to make it 3-2. Franklin Gutierrez's broken-bat RBI single to center tited it at 3.
Phil Hughes, scintillating since his move to the bullpen in early June, came in for the seventh and retired the Mariners in order, including getting Ken Griffey Jr. swinging on a 96-mph fastball.
Damon started the seventh by taking Jakubauskas' 1-and-2 pitch that was low and away and slapping it down the leftfield line for a ground rule double.l Rodriguez's blast made it 5-3.